CN210381423U

CN210381423U - Device for realizing macroscopic visualization of gas plasma in liquid

Info

Publication number: CN210381423U
Application number: CN201920505165.2U
Authority: CN
Inventors: 张伟; 王军锋; 王晓英; 霍元平
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2019-04-15
Filing date: 2019-04-15
Publication date: 2020-04-21
Anticipated expiration: 2029-04-15

Abstract

The utility model discloses a realize visual device of gaseous plasma macroscopical in liquid, including liquid container, be equipped with electrostatic nozzle and ring electrode in the liquid container, ring electrode is located the electrostatic nozzle directly over, air feeder and high voltage direct current power are connected respectively to the electrostatic nozzle, ring electrode ground connection, and liquid container adopts transparent material, the utility model discloses a device can realize that gaseous plasma macroscopical in the liquid phase is visual.

Description

Device for realizing macroscopic visualization of gas plasma in liquid

Technical Field

The utility model belongs to the technical field of plasma takes place, especially, relate to a device for realizing that gas plasma macroscopical visualization in liquid.

Background

Gas plasmas are widely present in universes such as mysterious bubble clouds in space, ionosphere and aurora on the earth's surface, and the like. The plasma is an ionized gas substance composed of atoms with part of electrons being deprived, positive and negative particles generated after the atoms and molecules are ionized, and is composed of ions, electrons and unionized neutral particles, and the whole substance is neutral. Meanwhile, the plasma is a good electric conductor and is composed of ionized conductive gas, which includes six typical particles, namely electrons, positive ions, negative ions, excited state atoms or molecules, ground state atoms or molecules, and photons.

Because the gas plasma has physical and chemical properties which are not possessed by conventional substances, the scientific direction of the gas plasma is paid much attention in the past 20 years, particularly the aspects of the stability, uniformity, chemical activity and interaction with substances of the plasma, and the like, and the application development of the gas plasma in various fields of material surface property change, wastewater treatment, clinical treatment, flow control, gas biological mutation breeding and the like is promoted through the established quantitative/semi-quantitative theoretical system and control strategy. However, since the gas plasma is difficult to be macroscopically visualized in actual exploration and application, and the interior of the gas plasma contains strong coupling of multiple physical fields and complex chemical processes, the basic mechanism of the gas plasma, such as mass and energy transfer processes, cannot be deeply explored at present, and a plurality of questions exist on the proposed related assumptions and theoretical models; based on the above, some related key scientific and technical problems are difficult to make substantial breakthrough, such as the chaos process of gas plasma, the development mechanism of nanosecond pulse discharge, the quantitative diagnosis of active particles of gas plasma, the biomedical effect of plasma, and the like.

At present, methods for generating gas plasma mainly include direct current discharge, pulse discharge, radio frequency discharge, microwave discharge, arc discharge and the like. Gas-liquid mixed discharge is an effective means for improving discharge application efficiency, generating free radicals and solving conductivity and energy consumption. The conventional gas-liquid mixed phase reactor mainly includes three structures. The first construction comprises a separate gas phase dielectric discharge reactor, wherein gas is injected into the liquid phase through a hollow electrode to form cloud-shaped small-size bubbles so as to enhance mass transfer between gas and liquid. The second configuration is to bubble gas into the liquid phase reactor at high pressure through a hollow needle electrode, with the generated radicals or radicals being transferred directly into the liquid. The third configuration is a fully miscible shape with the high voltage electrode in the gas phase and the low voltage electrode in the liquid, with the various active species generated in the gas phase transferring mass to the liquid phase. However, because the design of all three gas-liquid phase mixing reactors cannot fully utilize the point discharge characteristic, the gas phase reaction introduced into the liquid phase is mainly characterized in that along with the increase of the electric field intensity, the size of bubbles is reduced, and gas cannot be fully ionized to form macroscopic visual plasma. As is well known, in the vicinity of a tip electrode having a small radius of curvature, since the local electric field strength exceeds the ionization field strength of a medium, gas is more likely to be ionized and excited, and thus corona discharge is likely to occur, thereby generating plasma; and the smaller the curvature radius of the electrode is, the higher the field intensity in the vicinity thereof is, and the more easily the corona discharge phenomenon occurs.

SUMMERY OF THE UTILITY MODEL

The utility model discloses according to the problem that exists among the prior art, provided a realize the visual device of gas plasma macroscopical in liquid, aim at has realized that gas plasma macroscopical in the liquid phase is visual.

The utility model discloses the technical scheme who adopts as follows:

the device comprises a liquid container, wherein an electrostatic spray head and an annular electrode are arranged in the liquid container, the annular electrode is positioned right above a nozzle of the electrostatic spray head, the electrostatic spray head is respectively connected with a gas supply device and a high-voltage direct-current power supply, the annular electrode is grounded, and the liquid container is made of transparent materials.

Further, the gas supply device comprises a gas storage tank, and an outlet of the gas storage tank is sequentially connected with a valve, a connector and an electrostatic spray head.

Furthermore, the electrostatic spray head comprises a spray needle adjusting device, a spray head main body and a nozzle cap which are sequentially connected, wherein the spray head main body and the nozzle cap are provided with channels along the axial direction, the channels are nozzle inner cavities, and the side surface of the spray head main body is provided with a fluid inlet communicated with the nozzle inner cavities; the spray needle adjusting device is provided with a spray needle which is positioned in the inner cavity of the nozzle, and the top end of the spray needle is provided with a needle electrode.

Furthermore, the spray head main body, the nozzle cap and the spray needle adjusting device are all made of insulating materials.

Further, the included angle between the fluid inlet and the axis of the nozzle body ranges from 30 degrees to 60 degrees.

Furthermore, the needle-shaped electrode is made of tungsten wires, and the front end of the needle-shaped electrode is needle-shaped.

Furthermore, the spray needle adjusting device is in threaded connection with the spray head main body.

The utility model has the advantages that:

the utility model discloses make full use of the tip effect under the high-voltage electricity effect, produced local super high field intensity and made gaseous ionization and molecule chemical bond fracture to cause the surface tension sharply-increased of bubble, form plasma corona bubble in liquid. The gas flow in the pipeline can be adjusted by controlling a valve and a pressure reducing valve, the voltage of the system can be adjusted by controlling a high-voltage power supply, and the characteristics of the generated plasma bubbles are further controlled; the device designed by the utility model has simple structure, convenient installation and lower operation and maintenance cost.

The utility model discloses realized the macroscopic view of gas plasma in the liquid phase for the first time, be a major breakthrough in plasma research field. On the basis, a plurality of theories and hypotheses which are not verified in the field of plasmas can be evaluated through quantitative measurement and model establishment of the plasma bubbles, so that a theoretical research system of the plasmas is perfected, and the application of the plasmas in actual engineering is promoted. The whole device is simple to operate and easy to machine.

Drawings

FIG. 1 is a schematic view of the overall structure of the device of the present invention;

FIG. 2 is a schematic structural view of an electrostatic spray head according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the operation of the present invention;

FIG. 4 is a diagram showing the result of bubble collection according to the embodiment of the present invention;

fig. 5 is a diagram showing the result of plasma bubble collection according to the embodiment of the present invention;

fig. 6 is a diagram illustrating an evolution rule of bubble size according to an embodiment of the present invention;

in the figure, 1, a liquid container, 2, a high-voltage direct-current power supply, 3, grounding wires A, 4, a connector, 5, a flowmeter, 6, a valve, 7, a gas storage tank, 8, a pressure reducing valve, 9, an electrostatic spray head, 10, a plasma bubble, 11, a ring electrode, 12, a fixed metal rod, 13, grounding wires B, 14, a nozzle cap, 15, a fluid inlet, 16, a spray head main body, 17, a nozzle adjusting device, 18, a needle electrode, 19, a central threaded hole, 20 and a spray needle.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

As shown in fig. 1, the utility model provides a realize gaseous plasma macroscopic visualization's device in liquid, static shower nozzle 9 is equipped with to the bottom in liquid container 1, is equipped with annular electrode 11 directly over static shower nozzle 9, and fixed metal pole 12 is connected at the annular electrode 11 back, and fixed metal pole 12 passes through earth connection B13 ground connection, adds the solvent in liquid container 1 to anhydrous alcohol is the best, and the liquid level is higher than annular electrode 11.

As shown in fig. 2, the electrostatic sprayer 9 of the present invention includes a nozzle adjusting device 17, a sprayer main body 16 and a nozzle cap 14, the nozzle cap 14 is installed at the front end of the sprayer main body 16, the tail of the sprayer main body 16 is provided with a threaded hole for being in threaded fit with the outer surface of the nozzle adjusting device 17, the nozzle adjusting device 17 and the sprayer main body 16 are provided with the same through hole along the axial direction, the through hole is a nozzle inner cavity, the side surface of the sprayer main body 16 is provided with a fluid inlet 15 communicated with the nozzle inner cavity, and the fluid inlet 15 and the axis of the sprayer main body 16 have an inclination angle of 30-60 degrees; the needle adjusting device 17 is provided with a needle 20, the needle 20 is positioned in the inner cavity of the nozzle, and the needle electrode 18 is arranged on the top of the needle 20. Since the electrostatic head 9 requires a high voltage during operation, there is a risk of electric leakage, and in order to avoid damage to people and equipment due to electric leakage, the head main body 16, the nozzle cap 14, and the needle adjustment device 17 are made of an insulating material, preferably tetrafluoroethylene. The front end of the needle electrode 18 is precisely processed into a needle shape, the curvature radius is small, the used material is preferably tungsten wire, and the tungsten wire has the advantages of high melting point, large resistivity and high strength.

The bottom of the electrostatic spray head 9 is respectively connected with an air supply device and a high-voltage direct-current power supply 2, the high-voltage direct-current power supply 2 is grounded through a grounding wire A3, the air supply device comprises an air storage tank 7 which is connected with a connector 4 through a pipeline, the connector 4 is connected with the bottom of the electrostatic spray head 9, a pressure reducing valve 8 is arranged on the air storage tank 7, and the inlet pressure can be reduced to the required outlet pressure by changing the throttling area, adjusting the flow speed and the kinetic energy of fluid; and a valve 6 and a flowmeter 5 are also arranged on the pipeline of the gas storage tank 7, and the flowmeter 5 is used for monitoring the ventilation flow in the pipeline in real time.

For a more clear explanation of the technical solution protected by the present invention, the following is further explained in conjunction with the working process of the present invention:

when the valve 6 is opened, the gas in the pipeline begins to flow, the gas flows into the electrostatic spray head from the gas storage tank 7 through the connector 4 to enter the liquid in the liquid container 1, and the large-size drop-shaped bubbles are formed under the condition of no electric field. The high voltage dc power supply 2 is turned on, the voltage value is gradually increased, the size of the bubbles is gradually decreased, and when the applied voltage exceeds a certain value, the gas dispersion mode in the liquid shows that the bubbles in the micron level are rapidly converted into plasma bubbles in the millimeter level, as shown in fig. 3.

Fig. 4(a) shows an uncharged state, and the bubbles gradually decrease to micron-scale sizes as the electric field strength increases, as shown in fig. 4(b), 4(c) and 4 (d). The results of the embodiment collected under the condition of higher applied voltage are shown in fig. 5, and the air shows that the bubble size is sharply increased in the absolute ethyl alcohol, and plasma bubbles with stronger surface fluctuation are formed, as shown in fig. 5 (a); when the polarity of the electrodes is changed, the fluctuation degree of the plasma bubble surface is obviously reduced, as shown in fig. 5(b), which is mainly caused by the difference of electron and ion distribution and impact energy in the bubble. The utility model discloses improve discharge system device, fully considered tip effect, with thinner wire as the needle electrode 18 arrange the less electrostatic spray head 9 of diameter in, the electrostatic spray head 9 that the combination formed and the ring electrode 11 that floods in the liquid phase form the return circuit in inhomogeneous electric field, and 18 front end precision finishing of needle electrode are the acicular, have very little radius of curvature. As shown in fig. 6, under the action of the high-voltage electric field, bubbles formed by gas in the liquid phase gradually decrease in size as the electric field intensity increases, and are dispersed in the liquid phase; when the electric field strength exceeds a certain degree, the gas is fully ionized due to overhigh field strength near the tip of the needle-shaped electrode 18, and a large amount of positive ions and negative electrons generated after the gas is ionized are accelerated and impact the surface of the bubble by overhigh field strength and high-frequency current, so that the chemical bonds of gas molecules are broken and degraded, the surface area of the bubble is remarkably increased, the bubble is rapidly converted into a large-size corona bubble mode from an atomization mode, macroscopic visual low-temperature plasma is formed in the liquid, and the expression characteristics of the macroscopic visual low-temperature plasma are closely related to the electric field strength, the electrode polarity, the liquid, the gas type.

In practical application, the liquid container 1 can be made of transparent organic glass, in the research process of the plasma bubbles, a high-speed camera is used for capturing the basic form and the evolution process of the plasma bubbles, the flow field velocity distribution can be measured by using a particle imaging velocimetry technology, a mass spectrometer can be used for collecting the element components in the plasma bubbles, and the like. On the basis, a plurality of theories and hypotheses which are not verified in the field of plasmas can be evaluated through quantitative measurement and model establishment of the plasma bubbles, so that a theoretical research system of the plasmas is perfected, and the application of the plasmas in actual engineering is promoted.

The above embodiments are only used for illustrating the design ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, and the protection scope of the present invention is not limited to the above embodiments. Therefore, all the equivalent changes or modifications made according to the principles and design ideas disclosed by the present invention are within the protection scope of the present invention.

Claims

1. The utility model provides a realize gaseous plasma macroscopic visualization's device in liquid which characterized in that, includes liquid container (1), be equipped with electrostatic nozzle (9) and annular electrode (11) in liquid container (1), annular electrode (11) are located electrostatic nozzle (9) nozzle directly over, air feeder and high voltage direct current power supply (2) are connected respectively to electrostatic nozzle (9), annular electrode (11) ground connection, liquid container (1) adopts transparent material.

2. The device for realizing macroscopic visualization of gas plasma in liquid as recited in claim 1, wherein the gas supply device comprises a gas storage tank (7), and an outlet of the gas storage tank (7) is sequentially connected with a valve (6), a connector (4) and an electrostatic spray head (9).

3. The device for realizing the macroscopic visualization of the gas plasma in the liquid as claimed in claim 1, wherein the electrostatic spray head (9) comprises a spray needle adjusting device (17), a spray head main body (16) and a nozzle cap (14) which are connected in sequence, the spray head main body (16) and the nozzle cap (14) are provided with a channel along the axial direction, the channel is a nozzle inner cavity, and a fluid inlet (15) communicated with the nozzle inner cavity is arranged on the side surface of the spray head main body (16); the spray needle adjusting device (17) is provided with a spray needle (20), the spray needle (20) is positioned in the inner cavity of the nozzle, and the top end of the spray needle (20) is provided with a needle electrode (18).

4. A device for macroscopic visualization of a gas plasma in a liquid as recited in claim 3, wherein the showerhead body (16), the nozzle cap (14) and the needle adjusting means are all made of insulating materials.

5. An arrangement for performing macroscopic visualization of a gas plasma in a liquid according to claim 3, characterized in that the angle between the fluid inlet (15) and the axis of the showerhead body (16) ranges from 30 ° to 60 °.

6. An apparatus for realizing macroscopic visualization of gas plasma in liquid as recited in claim 3, 4 or 5, characterized in that the needle-shaped electrode (18) is made of tungsten wire, and the front end of the needle-shaped electrode (18) is needle-shaped.

7. An arrangement for performing macroscopic visualization of a gas plasma in a liquid according to claim 6, characterized in that the needle adjusting means (17) is screwed to the nozzle body (16).